Characterization of novel Ostreococcus tauri starch binding domains.

HEDIN, N; BARCHIESI, J; DIEGO FABIAN GOMEZ CASATI; BUSI, M. V.

Florianópolis

Congreso; IV SOLABIAA (Soc. Latinoam. de Biotecnología Ambiental y Algal) Latin American Congress; 2015

SOLABIAA

Starch Binding Domains (SBD) are one type ofcarbohydrate binding domains (CBM) that have acquired the evolutionaryadvantage of being able to interact and disrupt the substrate surface on aparticular way. This can be accomplished because this kind of CBM presents twopolysaccharide binding sites [1]. The proteins containing these CBMs show astrong physical association with the different substrates, increasing the rateof enzymatic reactions. These modules occur also in proteins with no hydrolyticactivity, constituting a core from which the catalytic proteins are organized[2]. These properties make SBDs a very powerful molecular tool, allowing to usthe possibility to engineering hydrolytic enzymes to increase its catalyticefficiencies when added in trans, and a powerful means of polysaccharidedestructuration.    In thiswork, we analyze the SBDs present in two degradative enzymes involved in starchcatabolism in Ostreococcus tauri. One of these SBD belongs to the family CBM20according to the CAZY classification (http://www.cazy.org/fam/acc_CBM.html).This SBD is part of the glucan 1,4-α-glucosidase (EC 3.2.1.3, Ot06g02060) thatcatalyze the hydrolysis of terminal 1,4-α-D-glucose residues from non-reducingends. The second SBD belongs to the family CBM48 of the CAZY classification andis present in the glycogen 6-alpha-D-glucanohydrolase (EC 3.2.1.68, Ot14g02550)that catalyze the hydrolysis of 1,6-α-D-glucosidic bonds in branchedpolysaccharides.